Floor cleaning appliance

ABSTRACT

The invention relates to a floor cleaning appliance comprising a suction turbine with a turbine wheel rotatingly drivable about a turbine axis, and a substantially horizontally aligned suction channel via which the suction turbine is in flow communication with a suction opening facing the floor surface to be cleaned, with the suction channel forming a container for collecting dirt and accommodating a dirt filter. In order to design the floor cleaning appliance with as low an overall height as possible, while achieving as strong a suction flow as possible in the area of the suction opening, it is proposed, in accordance with the invention, that the suction turbine be mounted on the suction channel with its turbine axis aligned at an incline to the vertical.

[0001] The present disclosure relates to the subject matter disclosed ininternational application PCT/EP02/02127 of Feb. 28, 2002, which isincorporated herein by reference in its entirety and for all purposes.

BACKGROUND OF THE INVENTION

[0002] The invention relates to a floor cleaning appliance comprising asuction turbine with a turbine wheel rotatingly drivable about a turbineaxis, and a substantially horizontally aligned suction channel via whichthe suction turbine is in flow communication with a suction openingfacing the floor surface to be cleaned, with the suction channel forminga container for collecting dirt and accommodating a dirt filter.

[0003] Such a floor cleaning appliance is known from the internationalapplication having publication number WO 99/28800. A suction flow can begenerated by the suction turbine for vacuum cleaning the floor surfaceto be cleaned. In the known floor cleaning appliance, the suctionturbine is mounted on the substantially horizontally extending suctionchannel with a vertically aligned turbine axis. This enables use of arelatively large turbine wheel, but has the disadvantage that the floorcleaning appliance has a considerable overall height.

[0004] The object of the present invention is to construct a floorcleaning appliance of the kind mentioned at the outset with as low anoverall height as possible, while achieving as strong a suction flow aspossible in the area of the suction opening.

SUMMARY OF THE INVENTION

[0005] This object is accomplished in a floor cleaning appliance of thegeneric kind, in accordance with the invention, in that the suctionturbine is mounted on the suction channel with its turbine axis alignedat an incline to the vertical. Owing to such alignment of the suctionturbine, the overall height of the floor cleaning appliance can be keptlow even when a relatively large turbine wheel is used. Moreover, suchan arrangement has the advantage that the suction flow brought about bythe suction turbine suffers only relatively low losses owing to changesin direction occurring in the area in which suction channel and suctionturbine are joined. As a result, a relatively strong suction flow can begenerated in the area of the suction opening. The floor cleaningappliance according to the invention is therefore characterized by acompact design and a particularly effective mode of operation.

[0006] It is of advantage for the turbine axis to be aligned at an angleof from approximately 15° to approximately 75° to the vertical. Inparticular, an angle of from approximately 20° to approximately 40° hasproven particularly expedient in order, on the one hand, to keep flowlosses occurring in the area of transition between the horizontallyaligned suction channel and the suction turbine low, and, on the otherhand, to enable use of as large a turbine wheel as possible, whiletaking into account as low an overall height as possible.

[0007] To achieve a particularly effective cleaning action, it is ofadvantage for the floor cleaning appliance to have a rotatingly drivablerotary brush arranged in the area of the suction opening. With therotary brush, both vacuum cleaning and brushing of the floor surface tobe cleaned are possible.

[0008] It is of advantage for the suction turbine to be in the form ofan axial-radial fan for drawing in the working air in axial direction inrelation to the turbine axis and giving it off in radial direction. Theuse of an axial-radial fan enables build-up of a high pressuredifference so a particularly strong suction flow is achievable.

[0009] As previously explained, the floor cleaning appliance accordingto the invention is characterized by a relatively low overall height.This makes it possible for areas of the floor surface to be cleanedunderneath radiators, pieces of furniture and the like to also bereached with the floor cleaning appliance. The working air drawn in bythe suction turbine is given off to the environment again after passingthrough the container for collecting dirt and the suction turbine. Inorder to prevent the working air that is given off from whirling up dirtdeposited, for example, on radiators, it is of advantage for the suctionturbine to comprise an outlet channel opening into at least one airoutlet opening and having an orifice area oriented at an incline to thevertical. By means of the orifice area oriented at an incline to thevertical, the exhaust air can be given off with an exhaust air flowhaving a correspondingly inclined orientation, which reduces the risk ofdirt deposited, for example, on radiators being picked up by the flow ofexhaust air when the floor cleaning appliance is positioned under theradiators.

[0010] It has proven advantageous for the orifice area of the outletchannel to be oriented at an angle of from approximately 60° toapproximately 80° in relation to the vertical.

[0011] To keep the noise generated by the floor cleaning appliance low,it has proven expedient for the outlet channel to surround the turbinewheel in circumferential direction. In spite of the floor cleaningappliance being designed as compactly as possible, this makes itpossible to use a relatively long outlet channel, whereby the noise madeby the suction turbine can be reduced. The use of a long outlet channelalso results in an increase in the pressure difference between inlet andoutlet of the suction turbine, whereby the efficiency of the suctionturbine is improved.

[0012] A particularly low generation of noise can be achieved by theoutlet channel being of spiral configuration and widening continuouslyin flow direction. With such a design, the exhaust air can expandcontinuously, thereby avoiding an abrupt expansion of the air with acorresponding generation of noise.

[0013] In a particularly preferred embodiment of the floor cleaningappliance according to the invention, provision is made for the suctionturbine to comprise an electric external rotor motor with a stator heldon a carrier element, and a rotor rotatable about the turbine axis, withthe turbine wheel held in a rotationally fixed manner on the rotor. Theuse of the external rotor motor makes it possible to position the motoron the side of the turbine wheel facing away from the suction channelwithout this resulting in any considerable increase in the overallheight of the floor cleaning appliance. This has, in turn, the advantagethat the suction channel does not have any considerable cross-sectionalconstrictions and is therefore characterized by as low a flow resistanceas possible.

[0014] The floor cleaning appliance is preferably of automotive design.To this end, it may comprise a chassis on which two drive wheels drivenby an electric motor are mounted.

[0015] The following description of a preferred embodiment of theinvention serves in conjunction with the drawings for furtherexplanation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 a schematic sectional view of a floor cleaning appliance;and

[0017]FIG. 2 a plan view of the floor cleaning appliance.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The drawings show an automotive floor cleaning appliancegenerally designated 10 with a chassis 12 in the form of a plasticinjection molded part on which there are rotatably mounted two drivewheels 13, 14, which are rotatingly drivable by an electric drive motor15 and 16, respectively.

[0019] A cover forming a dust guard, which for reasons of clarity is notshown in FIGS. 1 and 2, may be placed on the chassis 12.

[0020] The chassis 12 forms between the two drive wheels 13, 14 acarrier plate 21 which is oriented substantially parallel to a floorsurface 19 to be cleaned. The carrier plate 21 is followed in thedirection of travel 22 of the floor cleaning appliance 10 via a step 23by a supporting plate 24 which is also oriented parallel to the floorsurface 19 and by a front wall 25 oriented in the direction towards thefloor surface 19.

[0021] At a distance from the carrier plate 21, a base plate 26 is heldon the chassis 12 so as to be detachably connectable by detent elementswhich are known per se and are therefore not shown in the drawings.Supporting rollers 29 are freely rotatably mounted at the front end area27, in the direction of travel 22, of the base plate 26.

[0022] In its front area, the base plate 26 carries a sill 31 which dipsinto a suction opening 33 arranged in the base plate 26. A substantiallyhorizontally aligned suction channel 35 extending between the carrierplate 21, the step 23 and the supporting plate 24, on the one hand, andthe base plate 26, on the other hand, opens into the suction opening 33.A dirt filter 37 is held within the suction channel 35 so as to bealigned at an incline to the longitudinal direction thereof.

[0023] At its rear end area, the chassis 12 carries a suction turbine 40with a turbine housing upper part 41 and a turbine housing lower part 42accommodating between them a turbine wheel 44 and an electric turbinedrive 46.

[0024] The turbine drive 46 is in the form of an external rotor motorand comprises a stator 48 held in a rotationally fixed manner on theturbine housing upper part 41 and a rotor 49 rotatably held on thestator 48. The rotor 49 is in the form of a hood 50 engaging over thestator 48 and having permanent magnets 51 fixed on its inner side facingthe stator 48. The turbine wheel 44 is held in a rotationally fixedmanner on the bottom wall of the hood 50 facing away from the turbinehousing upper part 41.

[0025] The turbine wheel 44 is drivable by the turbine drive 46 so as tocarry out a rotational movement about a turbine axis 54. The turbineaxis 54 is aligned at an incline to the vertical and hence also at anincline to the longitudinal extent of the suction channel 35. An airinlet opening 56 of the suction turbine 40 is associated with theturbine wheel 44. The air inlet opening 56 is formed by a suction port58 which is integrally connected to the turbine housing lower part 42and establishes a flow connection between the suction channel 35 and theinterior of the suction turbine 40.

[0026] As will be apparent, in particular, from FIG. 2, the turbinewheel 44 is surrounded in circumferential direction by an outlet channel60 of spiral shape, which widens continuously in flow direction andopens into an air outlet opening 62. The orifice area 64 of the outletchannel 60 neighboring on the air outlet opening 62 is also oriented atan incline to the vertical.

[0027] By means of the suction turbine 40 a suction flow symbolized byarrows 66 can be generated within the suction channel 35 for conveyingdirt from the floor surface 19 to be cleaned through the suction opening33 into the suction channel 35. The area of the suction channel 35arranged upstream of the dirt filter 37 forms a container 67 forcollecting dirt.

[0028] In order to increase the dirt intake, a rotary brush 68 with anaxis of rotation aligned transversely to the direction of travel 22 andparallel to the floor surface 19 is held for rotation on the chassis 12in the area of the suction opening 33. The rotary brush 68 is driven byan electric brush drive 69 which is positioned on the supporting plate24 and is coupled to the rotary brush 68 by a drive belt known per seand therefore not shown in the drawings.

[0029] As the suction flow 66 suffers only low flow losses in the areaof the suction channel 35 and the suction port 58 oriented at an inclineto the vertical, a strong suction flow can be achieved in the area ofthe suction opening 33, which in combination with the rotary brush 68brings about effective floor cleaning. The dirt whirled up by the rotarybrush 68 is picked up by the suction flow and passed into the container67 for collecting dirt. The alignment of the suction turbine 40 with itsturbine axis 54 extending at an incline to the vertical enables use of arelatively large turbine wheel 44, but the overall height of the floorcleaning appliance 10 can be kept low.

1. Floor cleaning appliance comprising a suction turbine with a turbinewheel rotatingly drivable about a turbine axis, and a substantiallyhorizontally aligned suction channel via which the suction turbine is inflow communication with a suction opening facing the floor surface to becleaned, with the suction channel forming a container for collectingdirt and accommodating a dirt filter, wherein the suction turbine ismounted on the suction channel with the turbine axis aligned at anincline to the vertical.
 2. Floor cleaning appliance in accordance withclaim 1, wherein the turbine axis is aligned at an angle of fromapproximately 15° to approximately 75° to the vertical.
 3. Floorcleaning appliance in accordance with claim 1, wherein the floorcleaning appliance has a rotatingly drivable rotary brush arranged inthe area of the suction opening.
 4. Floor cleaning appliance inaccordance with claim 1, wherein the suction turbine is in the form ofan axial-radial fan.
 5. Floor cleaning appliance in accordance withclaim 1, wherein the suction turbine has an outlet channel which opensinto at least one air outlet opening, and the orifice area of which isaligned at an incline to the vertical.
 6. Floor cleaning appliance inaccordance with claim 5, wherein the outlet channel surrounds theturbine wheel in circumferential direction.
 7. Floor cleaning appliancein accordance with claim 6, wherein the outlet channel is of spiralconfiguration and widens continuously in flow direction.
 8. Floorcleaning appliance in accordance with claim 1, wherein the suctionturbine comprises an electric external rotor motor with a stator whichis held on a carrier element, and a rotor which is rotatable about theturbine axis and on which the turbine wheel is held in a rotationallyfixed manner.
 9. Floor cleaning appliance in accordance with claim 1,wherein the floor cleaning appliance is of automotive design.